Method for the separation of chemically modified rosins and their esters into components



' larly the separation of chemically modified rosin's" and their esters .into components by treatment I sults in, a. mixture of dihydro rosin; and tetra-I mea ure An -1 94i Patented Feb. 20, 1940 I 2,191,309 I: H METHOD FOR- THE SEPARATION on CHEMI- l OALLY MODIFIED ROSINS 'AND".THEIR 1 ESTERS INTO COMPONENTS Joserih' N. Borglin 'wilmington',Del; assigner to v Hercules"PowderfCompany, Wilmington, Del 7 a corporation oi" Delaware {No-Drawing. Application April 1,. 1939, I Serial No. 265,549

.sola'ims. ('01. 260-107) 'Ihis'1invention relates to a method :for'thef therein, as, for exam l byievaporatmg'the Se1ec I l separation of chemically modifiedv rosins and their'esters into components, andmore particuwith aselective solvent.

Due to the complexity of the chemioalTstruc-Q ture of rosin, treatments for the production'of chemical modifications practically. always .result' in products which are mixtures of two or more chemical compounds. unchanged rosin or the rosin may be converted into two or more different materials,' orboth. The .esterification of such a. modified product 1 produces a modified rosin ester which. similarly,

is a mixture of chemically difierent esters. Likewise, esterification'of rosin and then treatment to produce chemical modification, gives. a:,prod-. uct which is a mixture of chemically different esters. Thus, for-example, the hyc'lrogenation of. resin may result in amixtureoi unchanged rosin and] dihydro-rosin. More complete hydrogenation re hydro-rosin. Theproducti'on-of a product which is entirely tetrahydro-rosin has so fariprovedj impossible, The e'sterification' ofa hydrogenated rosin results in a' mixture ofrosin esters. Like-- wise, the hydrogenationof rosin esters results; in a mixture of ordinary rosin ester and dihydrorosin ester or a mixture oidihydro-rosin ester and. tetrahydro-rosin ester. v v

The separation of the chemicallydifierent c0m-;

ponentsof the chemically modified rosins has.

heretoforebeen practically impossible, and the.

Various commercial products have been complex mixturesof compounds of different chemical structure. No successful method forseparating the components. of such mixtures has-been developed, in spite of the fact thatit has been. may; i realized thatsuch separation would beof. great from a scientific standpoint. V

Now, I. have i'ound that I can separate chemically modified rosins' and chemically -modified rosin esters into their components by a method value from a commercial standpoint, as well as I which. is relatively simple, eflicient and. adaptable to commercialoperation. I accomplish this by treating a chemicallymodified rosin or 'a chemiw cally modified rosin ester with a substance se; lected from'the group ofsubstances now known to the. art to be selective solvents for the visible and latent color bodie's of rosin;

The process in accordanceyvith this invention consists of treating amodified rosin or modified rosin ester with a solvent which is a selective-solvent for the color. bodies of rosin, separating. the selective solvent from the undissolved component of the modified rosin or rosin ester and recover-I- ing. the component of the modifiedrosin dissolved The product. may contain tive solvent... This process. can be repeated as many times as necessary to produce the desired, separation of the components; I

i carryingout this me hod,.the. modified rosin orrosin-esters may or may some first dissolved.

in a solvent therefor which is. immiscible with the will be found convenientto use'a solvent,.p'articu selective solventiwhichis .used.;. .Ordinarily, it

larly if the modified rosin er rosin ester treated I is asolid at the'temperatureof treatment. When it is desired to use a solvent for I the modified rosinor modified rosin ester,- the procedure in accordance with this inventionjwill consist of dissolving the modifiedrosin. or'imodified rosin ester intheisolvent, contacting .the solution so formed with a selective rosin color bojdy solvent,

immiscible therewith, separating jthe'f two. solu-..

tions thus formed. and recovering a. component of the modified rosin or modified rosin ester from each solution as,, for example, by evaporating the respective solvents.) preferably under reduced pressure. This. procedure mav be, repeated as many times asd'esired.

The modified rosirror. modified'rosin ester. which I may treat accordance. this invention may be anyrosinlor rosin ester which'ha's been treated to modify its chemical structurd sojthat the resultant product is a mixture of two .or morechemically different substances. The, hydrogenation of rosin or a resin ester in the presence era suit- ,ablecatalyst accordingvto methods known to the art produces such. a {modified rosin or modified,

rosin. ester. v The esteri'fication of a hydrogenated rosin, likewise, produces such an "ester.

.The polymerization "of rosin or a rosin ester to increase its molecular weight and melting point by treatment with a polymerizing'agent, forjexaniple,volatile metal halides, as, boron trifluoride,

zinc v chloride, 'stanni'c chloride, aluminum 'chloride, ferric chloride; mineral ac dsgas; sulfuric acid, phosphoric acid; fullers .earth; .liydrogen fluoride'jacid salts, as. sodium acid sulfate, etc.i

metallicjsililcon; hydro fiu'oro-boricacid; etc., according tornethods known to the art, produces such a modified rosin or-modified rosin ester.

Such a modifiedrosin ester may'alsofbe produced by esterifyinga polymerized rosin;

L'Again, the treatment ofii'osin orv a rosin ester with a suitable catalyst, as, for examplefa hydro-5 genation catalyst, as nickel, asnickel chromite, platinum, pa11adium,,et.c at an elevated tempera .ture. of, ior example, trom'about C. to about- 200 C. and without reaction between the rosin or rosin ester and any added substance, to produce an intraand inter-molecular rearrangement within the hydrocarbon nucleus of the rosin or rosin ester with a reduction in the apparent unsaturation as disclosed in the co-pending application of Edwin E. Littmann, Serial No. 84,877, filed June 12, 1936, produces a modified rosin or modi fied rosin ester which may be treated in accordance with this invention. Such modified rosins p gasoline, petroleum ether, a normally gaseous petroleum hydrocarbon held in liquid phase by and modified rosin ester'will hereinafter be termed Hyex rosins and Hyex rosin esters, respectively. The esterification of a-Hyex rosin also produces such a chemically modified rosin ester.

The modified rosins which I treat in accordance with this invention may be any grade of woodor' gum' rosin which has been treated to modify its chemical structure so that the product is a mixture of two or more chemically difierent materials. The esters of the modified rosins which I treat may be produced by the esterification of modified rosins or maybe produced bythe chemical'modification of ordinary esters of rosins, and may be esters of either a monohydric or a polyhydric alcohol. Thus, esters of rosins withmonohydric alcohols, such as, for example, methanol, ethanol, propanol, butanol, amyl alcohol,,cetyl alcohol, lauryl alcohol, stearyl alcohol, furfuryl alcohol, hydrofurfuryl alcohol, abietanol, hydroabietanol, phenol, benzyl alcohol, etc., or with polyhydric alcohols, such as, for example, ethylene glycol, diethylene glycol, triethyleneglycol, glycerol, sorbitoLmannitol, erythritol, penta:

erythritol, method;

The selective solvent which I use in accordance with this-invention may be any of the various selective solvents for the visible and latent color bodies of rosins and rosin esters heretofore known. Thus, I may use furiural, furfuryl alcohol, a chlorohydrin, as, ethylene chlorohydrin, propylene chlorohydrin, etc., aniline, phenol, resorcinol, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, trimethylene glycol, glycerol, butyl' glycerol, ethyl formate, methyl acetate, methyl formate, methyl orthonitrobenzoate, methyl furoate, alkyl formate, monoacetin, diacetin, triacetin, ethylene glycol monoacetate, methanol, hydroxyl alkylamine, as triethanolamine, a solution of oxalic acid in water or in methanol, ethanol or other loweraliphatic alcohol,"ethyleneg1ycol monoethyl ether, or other immiscible glycol ether, ethylene glycol monoacetate, or other immiscible glycol ester, methyl thiocyanate, ethyl thiocyanate, acetonitrile, acetic acid, acetic anhydrlde, p-chloroaniline, resorcinol plus hydrosulphite, ethylene glycol diacetate, glycerol diaectate, resorcinol monoacetate, resorcinol diacetate, phenyl acetate, furfuryl acetate, ethylidine diacetate, n-propyl furoate, ethyl glycollate, methyl citrate, ethyl tartrate, ethyl malonate, methyl maleate, dimethyl phthalatepbenzyl formate, monobutyrin, ethyl carbonate, methyl lactate, diethyl oxalate, methyl adipate, hydroxyhydroquinone triacetate, methyl chlorocarbonate, propylene glycol monoacetate, hydroquinone diacetate, catechol monoacetate, guaiacyl acetate, methyl glutarate, ethyl oxalate, benzyl acetate, diethyl'glutacoate, ethyl lactate, diethyl phthalate, ethyl anisate, methyl salicylate, methyl cinnamate, methyl mandelate, methyl acrylate, ethyl oxamate, methyl succinate, ethyl propiolate, ethyl malate, methoxy-benzaldehyde, guaiacol, anisidin, nitroanisol, dichloroethyl ether, methoxy acetic acid, methy-oxybenzyla1- etc., may be treated by my new chemically non-reactive, etc.

The solvent in which I may dissolve the modified rosinor modified rosin ester before contacting it witha selective solvent may be any solvent for the modified, rosin or modified rosin ester which is immiscible and non-reactive. with the,

selective solvent used. Thus, I may use a petroleum hydrocarbon solvent, such as, for example,

elevated pressure, low temperature, or both. The

concentration of the modified rosin or modified rosin ester in such a solution may be within the range of about 5%=to about by weight, and desirably'within' the range of about 15% to about 30% by'weight.

The temperatm'e at which the process in accordance wit'n my invention may be carried out is dependent upon the selective solvent employed and will be within the range of about 10 C. to about +60 .0. In any case the temperature used will be such that the selective solvent is a liquid underthe pressure used.

In the embodiment of my process in which a chemically modified rosin or a chemically mocli-J fied rosin ester is dissolved in a solvent therefor before it is contacted with a selective solvent, the solution so formed may have a concentration within the range of about 5% to about 40%, by weight. Usually I prefer to use a solution having a concentration within the range of about 10 to about.25% ,by weight.

. The number of washes employed in my process may bevaried in accordance with the results desired, and it will be appreciated that the greater the number of washes given the sharper will be the separation of the components of the cheml- I callymodified rosin or chemically modified-rosin ester treated.

EXAMPLE I Wood rosin polymerized by treatmentin solution-'in-ethylene dichloride solution with aluminum chloride, washed with hydrochloric acid and then with water, and recovered by evaporation of the'solvent wastreated. One hundred grams of this polymerized rosin was dissolved in 300 grams of gasoline. This solution was washed with 75 ccyof-furfu ral, with 25 parts byvolume of furfural and thenwith two portions of 10 cc. of fur rural. -The furfural wash solutions were combinedand evaporated to recover the component of the polymerized rosin dissolved therein. Likewise, the gasoline solution was evaporated to recover the component remaining therein.

The two components thus separated from the original polymerized rosin and a sample of the original polymerized rosin were tested by making aiiansoo pared with about one hundred-and five days for.

the original polymerized-rosin; showing itito be chloride,into two components one of which isa highly polymerized and the other an; ordinary unpolymerized rosin.; i i

. EXAMPLE II 1 v I 7 .Wood rosin, "polymerizedi b y treatment with:

95% sulfuric acid and. having ;a drop .melting point of 103.5 C. and gradingH in color, was.

' treated. Three 250 gram portions of this-poly merized rosin Weredissolved separately in 750 grams of gasoline. tions was washed counter-currently at room tem-' perature with one 50' cc. and six 25cc. portions of furfural in'such a manner that each solution of polymerized rosin received four washes 'with furfural. The furfural wash solutions were combined to recover the component. ofthe polymeriized rosin dissolved therein. Eachof the three gasoline solutions was 'evaporatedseparately un; der reduced pressure to recover the component of the polymerized rosinrcmainin'gthereinl various components thus obtained wereanalyze'd with the results given in Table 1 below.

Table 1 I v I Drop Grams Color 1116112111" yield grade point Original polymerized rosin H 103. 5 Rosin from gasoline solution No. l. 52 M 100 Rosin from gasoline solution No. 2 71 K 100 Rosin from gasoline solution No. 3 J. 86 H,-1-, 99. 5 Fraction from combined furfural frac- I tions I 13 103 An examination of the above tabl'e shows that thetreatment of the polymerized .rosinsolution with furfural separated theoriginal: polymerized rosinwinto .two principal components, J one .of. which is lighter.coloredandofxa lowendegree of polymerization than the other 1:.

EXAMPLE III ucts thus secured showed the following results on analysis Table 2 Refractive Hydro index; .--genation Yleld i i i ;.Perce rrt Percent Original hydrogenated rosin 1.5255 60 1.. Fraction from-gasoline solution' 1 1 0. 1.52 18 {Ii-3;" $4.5, Fraction from gasoline solution o. 1. 5230 74 Fraction from gasoline solution o 1. 5243 68 Fraction tom combined furfural 1 fractions 1.538 22 An inspection of thesweetiesh wsjiiiana furfural wash removed unhydrogenatedQfor slight;- I 1y hydrogenatedwrosin from thehydrogenated rosin contained stheaa ine}s lut o r9 t at Each of the resulting soluthe" saturation of i the T hydrogenated rosin recovered from the" gasoline solution was increased (rosin was prepared. 'Three portions of this sol'i'ition', each '300 parts by volume, were counter currentlywashedwith one portion of 500 parts by volume and six portions of 25 parts by volume, respeo'tiv ely of 85% aqueous phenol, whereby each. rosinjsolution received four washes. 'The gasoline solutions, and the combined j'phenol solutions were evaporated under reduced pres-' sure to recover the rosin fractionsdissolved therein. f Analysis of the products so recovered showed them to 'have thefollowing physical properties:

Table 3 Drop Refrac- S v melting tive Peel- Yield point index M9 C. Percent Original Hyex rosin 83 1. 5426 Fraction from gasoline solution No. 1 72 1.5375 +52.3 17.5 Fraction from gasoline solution No. 2-; 78 1.5376 +53.4 22. 5 Fraction from.,gasoline i Solution No. 3 80. 5 j 1. 5400 +55. 4 31. 5 .Fraction'irom aqueous i phenol"-. ..se.o.- 1.539 +61.4 21.6

.eXaminatio-n of'the aboveitable showsfthat the treatment separated the original Hyexrosin into twocomponents havingquite different physicalchar-acteristics from one another. A comparison of" the properties of the component ,from gasoline solution 3 and those of the component from the aqueousphenol brings this out. Thus, 1

the aqueous phenol component had a definitely higher melting point, a lower refractive index,

and ahigher specific rotation, than the fraction: from the gasolinev solution.

. 3. -Azgasolin e solution containing 20 Hyex rosin was prepared. Three portions of-300 partsby volume each of the solutionv were counter-scurrently 'washedjwith 'oneportion of furfural or; fifty parts by volume and four portions of furfural of thirty partsby volume, so that each of.

Table 4 Drop Refrac- Specifmelting "5 tive ic ro- Yield point index tation Fraction from gaso- C. 1 Per cent line solution N0. 1. 75. 5 156. 5 1. 5371 +50. 0 21.6 Fraction from gaso- 'I i line Solution No. 2. I 77. 5 160. 5 '1. 5378 +54. 5 25. 6

Fraction from gasoline solution No.3. 82.0 163.0 1.5382 -+53.4 32.8 Fraction from fur- I furalsolutionflafl 90.0 161.5 1.5527 '+60.2

I lie he bov xr blee in a le we; 75

ample IV, the characteristics'of the separated components show them to be different types of rosin.

- EXAMPLE VI Three portions of'a 20% solution of hydrogenated I grade wood rosin in gasoline of 200 grams each were counter-currently washed with methyl thiocyanate at 25"v C., so that each gasoline solution received five washes with 20 cc. of methyl thiocyanate. The three refined gasoline solutions and the combined thiocyanate solutions were evaporated under reduced pressure to recover the rosin fractions dissolved in each. The analyses and yields of these fractions of the hydrogenated rosin, as well as that of the original hydrogenated rosin, are given in Table 5 which follows:

An inspection of the data of Table 5 shows that the treatment with the methyl thiocyanate solution separated the hydrogenated rosin having a saturation of 62.5% of theoretical into fractions having saturations within the range of 67-72% of theoretical on one hand and 30% of theoretical on the other. Thus, the thiocyanate tended to selectively dissolve unhydrogenated rosin from the more highly hydrogenated rosin which 'remained in the gasoline solution.

EXAMPLE VII Three portions of a 20% solution of. dihydro abietyl alcohol in gasoline of 50 grams each were counter-currently washed with methyl thiocyanate at C., so that each gasoline solution received five washes with 10 cc. portions of methyl thiocy'anate. The three refined gasoline solutions I this invention definitely concentrated the alcoholic portion of the original dihydroabietyl alcohol in the methyl 'thiocyanate fraction.

EXAMPLE VIII Three portions of 100 grams each of a 20% solution of dihydroabietyl alcohol in gasoline were washed counter-currently with aniline at 0 0., so that each gasoline solution received five Washes with 10 cc. portions of aniline. The three refined gasoline solutions and also the combined aniline solutions were evaporated under reduced pressure to recover the dissolved products. The analyses and yields of these products are given in Table 7 which follows:

Table 7 13.3.14. Hydroxyl Alcohol 335% recovered Percent Percent Grams Original dihydroabietyl alcohol"-.. 4. 75 81 Dihydroabietyl alcohol from gasoline solution N 0. l... 4. 4 75 9. Dihydroabietyl alcohol from gasoline solution No. 2 4. 65 78. 5 16.5 Dihydroabietyl alcohol from gasoline solution N o. 3 4. 7 80 19. 2 Dihyd'r'oabietyl alcohol from combined aniline solutions... 4. 75 82 ll. 3

An examination ofthe'above data shows that aniline, like the methyl thiocyanate of the Example VII selectively dissolved the dihydroabietyl alcohol, yielding a fraction which was materially purer than the original sample.

EXAMPLE IX A glycerol ester of hydrogenated wood rosin (hydroabietic acid) was dissolved in gasoline to a 20% concentration. Three portions of 200 cc. each of this 20% solution were counter-currently washed at 25 C.'so that each portion received six washes with 20 cc. portions of 85% phenol. The three refined gasoline solutions and the combined phenol solution were evaporated under reduced pressure. The analyses and yields of the fractions thus recovered are given in Table 8.

and the combined thiocyanate solutions were evaporated under reduced pressure to recover .the dissolvedfractions. The analyses and yields of these fractions of the dihydroabietyl alcohol are given-in Table 6. a

Table 6 Weight Hydroxyl Alcohol recovered D.H.A.

. .Per cent Per cent Grams Original dihydroabietyl alcohol. .4. 75 S1 Dihydroabietyl alcohol from gasoline solution No. l p 4. 4 43 0. 7 Dihydroabietyl alcohol from 'gasoline solution No. 2 4. 65 60 2. 0 Dihydroabietyl alcohol from gasoline solution No. 3 4. 7 80 11.8 Dihydroabietyl alcohol combined methyl thiocyanate solution 4. 8 91. 5 12. 3

An inspection of the data of Table 6 shows.

that the original sample of dihydroabietyl alcohol was 81% alcohol, while the fraction recovered from the combined methyl thiocyanatesolution was 91.5% dihydroabietyl alcohol. As compared with this the fraction recovered in the 'Nofl gasoline solution was only 75% dihydroabietyl alcohol. Thus, the treatment in accordance with H Table 8 Refractive index at Yield Grams Original glycerol ester 1. 5303 Ester from gasoline solution No. l 1. 5303 25 Ester from gasoline solution No. 2.. 1. 5305 35 Ester from gasoline solution N o. 3- 1. 5314 37 Ester from combined phenol extract 1. 5316 Since it is known that the less saturated products have higher refraction indices, a comparison of the refractive index of the original ester with that of the fraction secured from the combined phenol extract shows that the latter contains less saturated material than the original, and is a definitely different material.

' I EXAMPLE X The methyl ester of hydrogenated wood rosin (dihydroabietic, acid) was treated following exactly the same procedure as in Example IX with the exception that furfural, instead oil 85% phenol, was usedas a selective solvent. The analyses and yields of the recovered fractions of the ester are given'in Table 9.

An examination of the data givenin Table 9 shows that the hydrogenated abietyl ester was concentrated in the gasoline solution #1 while the unhydrogenated ester was concentrated in the furfural extract ExArirrLE XE I v The glycerol ester of Hyex wood rosin was dissolved in gasoline to produce a 20% solution;

Three portions of 200 grams each of this solu-J tion were counter-currently washed with furfural at room temperature (25 C.) so that each por-"-' tion received washes with 6 20. cc. portions of furfural. The gasoline solutions and the, combined furfural washes were I then evaporated underre'duced pressure. The analyses and yields of the recovered products-are given'in Table 10.

Table 10 Refractive index Yield Original glyceryl ester of Eye): l'OSlIl... 1. 5442 Ester fromgasoline solution No. 1.--- 1. 5432 25 Ester from gasoline solution No. 2.. l. 5435 38 Ester from gasoline solution No. 3 1. 5454 39 Ester from combined furfural ext 1 5552 21 A comparison of the refractive indices of the original ester, the fraction recovered from the #1 gasoline solution and the fraction recovered from. I the furfural solution, shows that the original ester of Hyei: rosin has been separated into two chemically different fractions by the furfural It will be understood that the above examples and details of operation are given by way of illustration only, and that the scope ofmy invention as herein broadly described and claimed is in no way limited thereby.

This application forms a continuation-in-part of my application, Serial No. 160,725,- filedAugust 24, 1937, entitled Separation of chemically modified rosin nents.

What I claim and desire ,to protect by Letters Patent is: I v o l. The method of separating polymerized rosin into its components, which comprises dissolving polymerized rosin in a solvent therefor, contact ing the solution so formedwitha selective'rosin color-body solvent immiscible with the said solution, separating the selective solvent therefrom and recovering-a component of the polymerized] rosin from each of the resulting solutions.=

2. The method of separating polymerized rosin;

ing the solvent.

and their esters into 'compo-' into its components, which comprisesdissolving polymerized rosin in a solvent therefor, contacting the solution so formed with a selective rosin.

color-body solvent immiscible with the said solu tion, separating the selective solvent therefrom and recovering a component of the polymerized rosin from each of the resulting solutionsby evaporating the solvent. i Y Y 3; The method. of separating polymerized rosin into its components, which comprises dissolving polymerized rosin in a: solvent therefoncontacting the solutionso formed with furfural, sepa rating the selective solvent therefrom and recovering a component of the polymerized rosin from each of the resulting solutions by evaporating the solvent.

4. The method of separating polymerized rosin into its components, which comprises dissolving polymerizedrosin in a solvent therefor, contacting the solution so formed with phenol, separating the selective solvent therefrom and recoverin'g a-comp'onent of the polymerized rosin from. each of the resulting solutions by evaporating the solvent.

P 5. The-method of separatingpolymerized rosin into its componentswhich comprises dissolving polymerized rosin in a solvent therefor, contacting the solution so formed with an alkyl thio cyanate,'separating theselective solvent therefrom and recovering a' component of the polymerized rosin from each of the resulting solutions by evaporating the solvent.

into its components, which comprises dissolving polymerized rosin in a petroleum hydrocarbon solvent, contacting the solution so formed with a selective rosin color-body solvent immiscible with the said solution, separating'the selective 6. The method of separating polymerized rosin",

solvent therefrom and recovering'a component of the polymerized rosin from each of the result ingsolutions by evaporating the solvent.

I 7. The method of separating polymerized rosin into its components, which comprises dissolving polymerized rosin in a petroleum hydrocarbon solvent, contacting the" solution so formed with furfural, separating the furfural therefrom and recovering a component of the polymerized rosin from each of the resulting solutions by evaporat- 8. The method of separating polymerized rosin into its components, which comprises dissolving polymerized rosin ina petroleum hydrocarbon solvent, contacting the solution so formed with phenol, separating the phenol therefrom and recovering acomponent of the polymerized *rosin from each of the resulting solutions by evaporating the solvent. I

- 9. The method of separating polymerized rosin into its. components, which comprises dissolving polymerized rosin in a petroleum hydrocarbon solvent, contacting the solution'so formed with an alkyl thiocyanate, separating the alkyl thiocyanate therefrom and recovering a component of the polymerized rosin from each of the resulting solutions by evaporating the solvent.

' JOSEPH N.'BORGLIN. 

